25 January 2010

More clues to understanding brain trauma

CTE, or Chronic Traumatic Encephalopathy, is a degenerative neurological condition which has been identified in athletes who sustained repeated blows to the head over time, such as boxers and football players. For reasons that are not yet fully understood, a bildup of a protein called "tau" occurs in the brain.

Some athletes with this condition have been known to suffer depression, memory loss, severe mood swings and dementia. Some were also prone to suicide.

For combat veterans, this can suggest a link between TBI and PTSD. It also points to the potential risk of vets with TBI developing CTE later in life.

Since 2000, about 160,000 servicemembers have been diagnosed with mild traumatic brain injuries, or concussions, caused by powerful explosions.

Whether troops will suffer the same long-term damage as head-crunching football players or punch-drunk boxers is of paramount importance to the military, whose researchers in recent years have also wondered about links between concussions on the battlefield and PTSD. The military is currently funding some 50 studies looking into TBI, PTSD and other brain disorders.

Military researchers are developing databases and studies that will follow troops with mild traumatic brain injuries to see if they exhibit neurological problems as they age, said Kelly, the neurologist, who is working with the military as part of the Defense Centers of Excellence for Psychological Health and Traumatic Brain Injuries. ...

When a bomb explodes, violent waves of air called overpressures can rupture hollow organs, such as the intestines and lungs, and bruise solid organs. The force also affects the brain’s structure and functioning, said Dr. Shawna Scully, an Army major and chief of neurology at Landstuhl Regional Medical Center in Germany.

“There is going to be a question now,” Scully said. “Are there links between repeated exposure to concussion in the combat environment that could be culminating in a risk to our servicemembers in the future?”

Omalu said combat veterans who suffer head trauma from their proximity to blasts will likely receive the same type of jolts — quick acceleration and deceleration forces of the brain slamming into the skull — as football players or boxers do. Neurologist Dr. Ann McKee, who has examined the brains of several former athletes as the director of neuropathology services for the New England Veterans Administration, thought likewise.

“Some of the injury is probably quite similar,” she said, “but I would have to examine individuals who have had blast injuries.”

All the doctors interviewed agreed that there is scant information about how blasts affect the brain, since it’s only recently that combat vets have been able to survive such blasts in large numbers, thanks to improvements in body armor and better first aid on the battlefield.

Also, blasts damage many parts of the body, and troops injured in them often arrive at hospitals with gashes from shrapnel, profuse blood loss, severed limbs, damaged lungs, burns and often more than one of the above. All these injuries can alter the brain’s ability to function, Scully said.

Much more research needs to be done, and currently the only way to diagnose CTE is through an autopsy. But these findings open up a whole new research front.